add cache system

LeStorage/Codables/Log.swift

@@ -23,13 +23,13 @@ class Log: SyncedModelObject, SyncedStorable {
     }
 
     var id: String = Store.randomId()
-
     var date: Date = Date()
-    
+    var user: String? = nil
     var message: String = ""
 
-    init(message: String) {
+    init(message: String, user: String?) {
         self.message = message
+        self.user = user
         super.init()
     }
     
@@ -38,6 +38,7 @@ class Log: SyncedModelObject, SyncedStorable {
     enum CodingKeys: String, CodingKey {
         case id
         case date
+        case user
         case message
     }
     
@@ -45,6 +46,7 @@ class Log: SyncedModelObject, SyncedStorable {
         let container = try decoder.container(keyedBy: CodingKeys.self)
         id = try container.decode(String.self, forKey: .id)
         date = try container.decode(Date.self, forKey: .date)
+        user = try container.decodeIfPresent(String.self, forKey: .user)
         message = try container.decode(String.self, forKey: .message)
         try super.init(from: decoder)
     }
@@ -53,16 +55,17 @@ class Log: SyncedModelObject, SyncedStorable {
         var container = encoder.container(keyedBy: CodingKeys.self)
         try container.encode(id, forKey: .id)
         try container.encode(date, forKey: .date)
+        try container.encodeIfPresent(user, forKey: .user)
         try container.encode(message, forKey: .message)
         try super.encode(to: encoder)
     }
     
     func copy(from other: any Storable) {
         guard let log = other as? Log else { return }
-
         self.date = log.date
         self.message = log.message
     }
+    
     public func copyForUpdate(from other: any Storable) {
         fatalError("should not happen")
     }

LeStorage/Storable.swift

@@ -37,6 +37,8 @@ public protocol Storable: Codable, Identifiable, NSObjectProtocol {
     static func parentRelationships() -> [Relationship]
     static func childrenRelationships() -> [Relationship]
 
+    /// Denotes a data that own its own store
+    /// Effectively used to trigger directory creation when adding an item to the collection
     static func storeParent() -> Bool
     
 }

LeStorage/Store.swift

@@ -142,13 +142,13 @@ final public class Store {
     /// - Parameters:
     ///   - indexed: Creates an index to quickly access the data
     ///   - inMemory: Indicates if the collection should only live in memory, and not write into a file
-    public func registerSynchronizedCollection<T : SyncedStorable>(indexed: Bool = false, inMemory: Bool = false, limit: Int? = nil, synchronousLoading: Bool = false, noLoad: Bool = false) -> SyncedCollection<T> {
+    public func registerSynchronizedCollection<T : SyncedStorable>(indexed: Bool = false, inMemory: Bool = false, limit: Int? = nil, noLoad: Bool = false) -> SyncedCollection<T> {
         
         if let collection: SyncedCollection<T> = try? self.syncedCollection() {
             return collection
         }
         
-        let collection = SyncedCollection<T>(store: self, indexed: indexed, inMemory: inMemory, limit: limit, synchronousLoading: synchronousLoading, noLoad: noLoad)
+        let collection = SyncedCollection<T>(store: self, indexed: indexed, inMemory: inMemory, limit: limit, noLoad: noLoad)
         self._collections[T.resourceName()] = collection
         self._baseCollections[T.resourceName()] = collection.collection
 
@@ -225,14 +225,6 @@ final public class Store {
         throw StoreError.collectionNotRegistered(type: T.resourceName())
     }
     
-    /// Returns a collection by type
-//    func collection<T: Storable>() throws -> BaseCollection<T> {
-//        if let collection = self._collections[T.resourceName()] as? BaseCollection<T> {
-//            return collection
-//        }
-//        throw StoreError.collectionNotRegistered(type: T.resourceName())
-//    }
-    
     func registerOrGetSyncedCollection<T: SyncedStorable>(_ type: T.Type) -> SyncedCollection<T> {
         do {
             return try self.syncedCollection()
@@ -282,7 +274,7 @@ final public class Store {
     // MARK: - Synchronization
     
     fileprivate func _requestWrite<T: SyncedStorable>(type: T.Type) {
-        self._baseCollections[T.resourceName()]?.requestWrite()
+        self._baseCollections[T.resourceName()]?.requestWriteIfNecessary()
     }
     
     @MainActor
@@ -331,16 +323,6 @@ final public class Store {
         }
         self._requestWrite(type: T.self)
 
-        
-//        for identifier in identifiers {
-//            do {
-//                try self.deleteNoSyncNoCascade(type: type, id: identifier.modelId)
-//            } catch {
-//                Logger.error(error)
-//            }
-//            self.storeCenter.cleanupDataLog(dataId: identifier.modelId)
-//        }
-//        self._requestWrite(type: T.self)
     }
     
     fileprivate func _instance<T: SyncedStorable>(id: String, type: T.Type) -> T? {
@@ -348,31 +330,12 @@ final public class Store {
         return self.findById(realId)
     }
     
-    /// Calls deleteById from the collection corresponding to the instance
-//    func deleteNoSync<T: Storable>(instance: T) {
-//        do {
-//            let collection: BaseCollection<T> = try self.collection()
-//            collection.delete(instance: instance)
-//        } catch {
-//            Logger.error(error)
-//        }
-//    }
-    
     /// Calls deleteById from the collection corresponding to the instance
     func deleteNoSyncNoCascadeNoWrite<T: SyncedStorable>(type: T.Type, id: String) throws {
         let collection: SyncedCollection<T> = try self.syncedCollection()
         collection.deleteByStringId(id, actionOption: .noCascadeNoWrite)
     }
     
-    /// Calls deleteById from the collection corresponding to the instance
-//    func referenceCount<T: SyncedStorable>(type: T.Type, id: String) -> Int {
-//        var count: Int = 0
-//        for collection in self._collections.values {
-//            count += collection.referenceCount(type: type, id: id)
-//        }
-//        return count
-//    }
-    
     func isReferenced<T: Storable, S: Storable>(collectionType: S.Type, type: T.Type, id: String) -> Bool {
         if let collection = self._baseCollections[S.resourceName()] {
             return collection.hasParentReferences(type: type, id: id)
@@ -462,18 +425,6 @@ final public class Store {
         }
     }
     
-//    public func deleteDependencies<T: Storable>(type: T.Type, actionOption: ActionOption, _ isIncluded: (T) -> Bool) {
-//        
-//        do {
-//            let collection: any SomeCollection = try self.someCollection(type: type)
-//            if let syncCollection = collection as? SyncedCollection<T> {
-//            collection.deleteDependencies(actionOption: actionOption, isIncluded)
-//        } catch {
-//            Logger.error(error)
-//        }
-//        
-//    }
-    
     // MARK: - Write
     
     /// Returns the directory URL of the store

LeStorage/StoreCenter.swift

@@ -44,7 +44,7 @@ public class StoreCenter {
     fileprivate var _apiCallCollections: [String: any SomeCallCollection] = [:]
 
     /// A collection of DataLog objects, used for the synchronization
-    lazy fileprivate var _deleteLogs: StoredCollection<DataLog> = { self.mainStore.registerCollection() }()
+    fileprivate var _deleteLogs: StoredCollection<DataLog>? = nil
 
     /// A synchronized collection of DataAccess
     fileprivate(set) var dataAccessCollection: SyncedCollection<DataAccess>? = nil
@@ -96,6 +96,7 @@ public class StoreCenter {
         
         self.useWebsockets = webSockets
         self.useSynchronization = useSynchronization
+        self._deleteLogs = self.mainStore.registerCollection()
 
         let urlManager: URLManager = URLManager(secureScheme: secureScheme, domain: domain)
         self._urlManager = urlManager
@@ -145,6 +146,12 @@ public class StoreCenter {
     public var websocketFailure: Bool {
         return self._webSocketManager?.failure ?? true
     }
+    public var websocketError: Error? {
+        return self._webSocketManager?.error
+    }
+    public var websocketReconnectAttempts: Int {
+        return self._webSocketManager?.reconnectAttempts ?? 0
+    }
     
     public var apiURL: String? {
         return self._urlManager?.api
@@ -259,7 +266,7 @@ public class StoreCenter {
 
         self._storeLibrary.reset()
         self.dataAccessCollection?.reset()
-        self._deleteLogs.reset()
+        self._deleteLogs?.reset()
         
         self._settingsStorage.update { settings in
             settings.username = nil
@@ -808,7 +815,10 @@ public class StoreCenter {
 
     /// Returns whether a data has already been deleted by, to avoid inserting it again
     func hasAlreadyBeenDeleted<T: Storable>(_ instance: T) -> Bool {
-        return self._deleteLogs.contains(where: {
+        guard let deleteLogs = self._deleteLogs else {
+            fatalError("missing delete logs collection")
+        }
+        return deleteLogs.contains(where: {
             $0.dataId == instance.stringId && $0.operation == .delete
         })
     }
@@ -861,8 +871,11 @@ public class StoreCenter {
 
     /// Deletes a data log by data id
     func cleanupDataLog(dataId: String) {
-        let logs = self._deleteLogs.filter { $0.dataId == dataId }
+        guard let deleteLogs = self._deleteLogs else {
-        self._deleteLogs.delete(contentOfs: logs)
+            return
+        }
+        let logs = deleteLogs.filter { $0.dataId == dataId }
+        deleteLogs.delete(contentOfs: logs)
     }
 
     /// Creates a delete log for an instance
@@ -870,7 +883,7 @@ public class StoreCenter {
         let dataLog = DataLog(dataId: instance.stringId,
                               modelName: String(describing: T.self),
                               operation: .delete)
-        self._deleteLogs.addOrUpdate(instance: dataLog)
+        self._deleteLogs?.addOrUpdate(instance: dataLog)
     }
 
     /// Returns the appropriate store for a relationship
@@ -1184,21 +1197,11 @@ public class StoreCenter {
     /// Logs a message in the logs collection
     public func log(message: String) {
         DispatchQueue.main.async {
-            let log = Log(message: message)
+            let log = Log(message: message, user: self.userId)
             self._logsCollection().addOrUpdate(instance: log)
         }
     }
 
-    // MARK: - Migration
-
-    /// Migrates the token from the provided service to the main Services instance
-//    public func migrateToken(_ services: Services) throws {
-//        guard let userName = self.userName() else {
-//            return
-//        }
-//        try self.service().migrateToken(services, userName: userName)
-//    }
-
     deinit {
         NotificationCenter.default.removeObserver(self)
     }

LeStorage/StoredCollection.swift

@@ -25,7 +25,7 @@ public protocol SomeCollection<Item>: Identifiable {
     func deleteDependencies(actionOption: ActionOption, _ isIncluded: (Item) -> Bool)
 
     func findById(_ id: Item.ID) -> Item?
-    func requestWrite()
+    func requestWriteIfNecessary()
 }
 
 protocol CollectionDelegate<Item> {
@@ -81,15 +81,16 @@ public class StoredCollection<T: Storable>: SomeCollection {
     /// Indicates whether the collection has changed, thus requiring a write operation
     fileprivate var _triggerWrite: Bool = false {
         didSet {
-            if self._triggerWrite == true && self.inMemory == false {
+            if self._triggerWrite == true {
-
                 self._scheduleWrite()
-                DispatchQueue.main.async {
-                    NotificationCenter.default.post(
-                        name: NSNotification.Name.CollectionDidChange, object: self)
-                }
                 self._triggerWrite = false
             }
+
+            DispatchQueue.main.async {
+                NotificationCenter.default.post(
+                    name: NSNotification.Name.CollectionDidChange, object: self)
+            }
+
         }
     }
 
@@ -99,8 +100,6 @@ public class StoredCollection<T: Storable>: SomeCollection {
     /// Sets a max number of items inside the collection
     fileprivate(set) var limit: Int? = nil
 
-    fileprivate var _delegate: (any CollectionDelegate<T>)? = nil
-    
     init(store: Store, inMemory: Bool = false) async {
         self.store = store
         if self.inMemory == false {
@@ -108,24 +107,19 @@ public class StoredCollection<T: Storable>: SomeCollection {
         }
     }
     
-    init(store: Store, indexed: Bool = false, inMemory: Bool = false, limit: Int? = nil, synchronousLoading: Bool = false, noLoad: Bool = false, delegate: (any CollectionDelegate<T>)? = nil) {
+    init(store: Store, indexed: Bool = false, inMemory: Bool = false, limit: Int? = nil, noLoad: Bool = false) {
         if indexed {
             self._indexes = [:]
         }
         self.inMemory = inMemory
         self.store = store
         self.limit = limit
-        self._delegate = delegate
 
         if noLoad {
             self.hasLoaded = true
         } else {
             Task {
-                if synchronousLoading {
+                await self.load()
-                    await self.loadFromFile()
-                } else {
-                    await self.load()
-                }
             }
         }
         
@@ -149,8 +143,10 @@ public class StoredCollection<T: Storable>: SomeCollection {
     // MARK: - Loading
 
     /// Sets the collection as changed to trigger a write
-    public func requestWrite() {
+    public func requestWriteIfNecessary() {
-        self._triggerWrite = true
+        if self.inMemory == false {
+            self._triggerWrite = true
+        }
     }
 
     /// Migrates if necessary and asynchronously decodes the json file
@@ -158,19 +154,31 @@ public class StoredCollection<T: Storable>: SomeCollection {
         if !self.inMemory {
             await self.loadFromFile()
         } else {
-            await self._delegate?.loadingForMemoryCollection()
             await MainActor.run {
                 self.setAsLoaded()
             }
         }
     }
 
-    /// Starts the JSON file decoding synchronously or asynchronously
+    /// Starts the JSON file decoding asynchronously
     func loadFromFile() async {
         do {
             try await self._decodeJSONFile()
         } catch {
             Logger.error(error)
+            await MainActor.run {
+                self.setAsLoaded()
+            }
+            do {
+                let fileURL = try self.store.fileURL(type: T.self)
+                let jsonString: String = try FileUtils.readFile(fileURL: fileURL)
+                if !jsonString.isEmpty {
+                    StoreCenter.main.log(message: "Could not decode: \(jsonString)")
+                }
+            } catch {
+                
+            }
+
         }
     }
 
@@ -204,11 +212,10 @@ public class StoredCollection<T: Storable>: SomeCollection {
     
     /// Sets a collection of items and indexes them
     func setItems(_ items: [T]) {
-        self.items.removeAll()
+        self.clear()
         for item in items {
             self._addItem(instance: item)
         }
-        self.requestWrite()
     }
     
     @MainActor
@@ -220,7 +227,7 @@ public class StoredCollection<T: Storable>: SomeCollection {
             self.setAsLoaded()
             self.addOrUpdate(contentOfs: items)
         }
-        
+        self.requestWriteIfNecessary()
     }
 
     /// Updates the whole index with the items array
@@ -236,7 +243,7 @@ public class StoredCollection<T: Storable>: SomeCollection {
     /// Adds it if its id is not found, and otherwise updates it
     @discardableResult public func addOrUpdate(instance: T) -> ActionResult<T> {
         defer {
-            self.requestWrite()
+            self.requestWriteIfNecessary()
         }
         return self._rawAddOrUpdate(instance: instance)
     }
@@ -245,7 +252,7 @@ public class StoredCollection<T: Storable>: SomeCollection {
     public func addOrUpdate(contentOfs sequence: any Sequence<T>, _ handler: ((ActionResult<T>) -> ())? = nil) {
 
         defer {
-            self.requestWrite()
+            self.requestWriteIfNecessary()
         }
 
         for instance in sequence {
@@ -268,9 +275,9 @@ public class StoredCollection<T: Storable>: SomeCollection {
     /// A method the treat the collection as a single instance holder
     func setSingletonNoSync(instance: T) {
         defer {
-            self.requestWrite()
+            self.requestWriteIfNecessary()
         }
-        self.items.removeAll()
+        self.clear()
         self._addItem(instance: instance)
     }
 
@@ -326,7 +333,8 @@ public class StoredCollection<T: Storable>: SomeCollection {
             self.addPendingOperation(method: .add, instance: instance, actionOption: actionOption)
             return false
         }
-        
+        self.invalidateCache()
+
         self._affectStoreIdIfNecessary(instance: instance)
         self.items.append(instance)
         instance.store = self.store
@@ -352,6 +360,7 @@ public class StoredCollection<T: Storable>: SomeCollection {
             self.addPendingOperation(method: .update, instance: instance, actionOption: actionOption)
             return false
         }
+        self.invalidateCache()
 
         let item = self.items[index]
         if item !== instance {
@@ -401,6 +410,7 @@ public class StoredCollection<T: Storable>: SomeCollection {
     }
     
     func localDeleteOnly(instance: T) {
+        self.invalidateCache()
         self.items.removeAll { $0.id == instance.id }
         self._indexes?.removeValue(forKey: instance.id)
     }
@@ -418,7 +428,7 @@ public class StoredCollection<T: Storable>: SomeCollection {
             self.deleteItem(instance, actionOption: actionOption)
         }
         if actionOption.write {
-            self.requestWrite()
+            self.requestWriteIfNecessary()
         }
     }
     
@@ -430,12 +440,12 @@ public class StoredCollection<T: Storable>: SomeCollection {
         return self.items.first(where: { $0.id == id })
     }
 
-    /// Proceeds to "hard" delete the items without synchronizing them
+    /// Deletes a list of items
-    /// Also removes related API calls
     public func deleteDependencies(_ items: any Sequence<T>) {
         defer {
-            self.requestWrite()
+            self.requestWriteIfNecessary()
         }
+        self.invalidateCache()
         let itemsArray = Array(items) // fix error if items is self.items
         for item in itemsArray {
             if let index = self.items.firstIndex(where: { $0.id == item.id }) {
@@ -489,7 +499,6 @@ public class StoredCollection<T: Storable>: SomeCollection {
                 self.deleteUnusedShared(data, actionOption: item.actionOption)
             }
             
-            self._delegate?.itemMerged(item)
         }
         manager.reset()
         
@@ -528,12 +537,13 @@ public class StoredCollection<T: Storable>: SomeCollection {
 
     /// Simply clears the items of the collection
     public func clear() {
+        self.invalidateCache()
         self.items.removeAll()
     }
 
     /// Removes the items of the collection and deletes the corresponding file
     public func reset() {
-        self.items.removeAll()
+        self.clear()
         self.store.removeFile(type: T.self)
     }
 
@@ -562,10 +572,35 @@ public class StoredCollection<T: Storable>: SomeCollection {
     func updateLocalInstance(_ serverInstance: T) {
         if let localInstance = self.findById(serverInstance.id) {
             localInstance.copy(from: serverInstance)
-            self.requestWrite()
+            self.requestWriteIfNecessary()
         }
     }
     
+    // MARK: - Cached queries
+    
+    fileprivate var _cacheVersion = 0
+    fileprivate var _queryCache: [AnyHashable: (version: Int, result: Any)] = [:]
+    
+    // Generic query method with caching
+    public func cached<Result>(
+        key: AnyHashable,
+        compute: ([T]) -> Result
+    ) -> Result {
+        if let cached = self._queryCache[key],
+           cached.version == self._cacheVersion,
+           let result = cached.result as? Result {
+            return result
+        }
+        
+        let result = compute(items)
+        self._queryCache[key] = (self._cacheVersion, result)
+        return result
+    }
+    
+    private func invalidateCache() {
+        self._cacheVersion += 1
+    }
+    
 }
 
 extension StoredCollection: RandomAccessCollection {

LeStorage/SyncedCollection.swift

@@ -19,10 +19,10 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
     let store: Store
     let collection: StoredCollection<T>
     
-    init(store: Store, indexed: Bool = false, inMemory: Bool = false, limit: Int? = nil, synchronousLoading: Bool = false, noLoad: Bool = false) {
+    init(store: Store, indexed: Bool = false, inMemory: Bool = false, limit: Int? = nil, noLoad: Bool = false) {
         
         self.store = store
-        self.collection = StoredCollection<T>(store: store, indexed: indexed, inMemory: inMemory, limit: limit, synchronousLoading: synchronousLoading, noLoad: noLoad)
+        self.collection = StoredCollection<T>(store: store, indexed: indexed, inMemory: inMemory, limit: limit, noLoad: noLoad)
         
     }
     
@@ -42,19 +42,6 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         return SyncedCollection<T>(store: Store(storeCenter: StoreCenter.main))
     }
    
-    /// Migrates if necessary and asynchronously decodes the json file
-//    override func load() async {
-//        do {
-//            if self.inMemory {
-//                try await self.loadDataFromServerIfAllowed()
-//            } else {
-//                await self.loadFromFile()
-//            }
-//        } catch {
-//            Logger.error(error)
-//        }
-//    }
-    
     /// Loads the collection using the server data only if the collection file doesn't exists
     func loadCollectionsFromServerIfNoFile() async throws {
         let fileURL: URL = try self.store.fileURL(type: T.self)
@@ -190,41 +177,6 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         return batch
     }
     
-    /// Deletes an instance without writing, logs the operation and sends an API call
-//    fileprivate func _deleteNoWrite(instance: T) {
-//        self.deleteItem(instance, shouldBeSynchronized: true)
-//        self.storeCenter.createDeleteLog(instance)
-////        await self._sendDeletion(instance)
-//    }
-    
-//    public func deleteDependencies(_ items: any RandomAccessCollection<T>, actionOption: ActionOption) {
-//        guard items.isNotEmpty else { return }
-//        if actionOption.synchronize {
-//            self.delete(contentOfs: items)
-//        } else {
-//            self.deleteNoSync(contentOfs: items)
-//        }
-//    }
-    
-//    public func deleteDependencies(_ items: any Sequence<T>) {
-//        
-//        self.collection.deleteDependencies(items)
-//        
-////        super.deleteDependencies(items)
-//        
-//        let batch = OperationBatch<T>()
-//        batch.deletes = Array(items)
-//        Task { await self._sendOperationBatch(batch) }
-//    }
-    
-//    public func deleteDependenciesAsync(_ items: any Sequence<T>) async {
-//        super.deleteDependencies(items)
-//        
-//        let batch = OperationBatch<T>()
-//        batch.deletes = Array(items)
-//        await self._sendOperationBatch(batch)
-//    }
-    
     fileprivate func _cleanUpSharedDependencies() {
         for relationship in T.relationships() {
             if let syncedType = relationship.type as? (any SyncedStorable.Type) {
@@ -246,11 +198,6 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         case .child:
             throw StoreError.invalidStoreLookup(from: type, to: relationship.type)
         }
-//        if relationship.storeLookup {
-//            store = self.store.storeCenter.mainStore
-//        } else {
-//            store = self.store
-//        }
 
         let collection: SyncedCollection<S> = try store.syncedCollection()
         collection._deleteUnusedGrantedInstances(originStoreId: originStoreId)
@@ -326,11 +273,6 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         self.collection.addOrUpdate(contentOfs: sequence)
     }
     
-    /// Deletes the instance in the collection without synchronization
-//    func deleteNoSync(instance: T) {
-//        self.collection.delete(instance: instance)
-//    }
-    
     public func deleteNoSync(contentOfs sequence: any RandomAccessCollection<T>) {
         self.collection.delete(contentOfs: sequence)
     }
@@ -346,16 +288,6 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         instance.deleteUnusedSharedDependencies(store: self.store)
     }
     
-    /// Deletes the instance in the collection without synchronization
-//    func deleteNoSyncNoCascade(id: String) {
-//        self.collection.deleteByStringId(id, actionOption: .standard)
-//    }
-//    
-//    /// Deletes the instance in the collection without synchronization
-//    func deleteNoSyncNoCascadeNoWrite(id: String) {
-//        self.collection.deleteByStringId(id, actionOption: .noCascadeNoWrite)
-//    }
-    
     func deleteByStringId(_ id: String, actionOption: ActionOption = .standard) {
         self.collection.deleteByStringId(id, actionOption: actionOption)
     }
@@ -431,10 +363,6 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
     
     /// Adds or update an instance if it is newer than the local instance 
     func addOrUpdateIfNewer(_ instance: T, shared: SharingStatus?) {
-                
-//        defer {
-//            self.triggerWrite()
-//        }
 
         if let index = self.collection.items.firstIndex(where: { $0.id == instance.id }) {
             let localInstance = self.collection.items[index]
@@ -485,8 +413,17 @@ public class SyncedCollection<T : SyncedStorable>: SomeSyncedCollection, Collect
         return self.collection.items
     }
     
-    public func requestWrite() {
+    public func requestWriteIfNecessary() {
-        self.collection.requestWrite()
+        self.collection.requestWriteIfNecessary()
+    }
+    
+    // MARK: - Cached queries
+    
+    public func cached<Result>(
+        key: AnyHashable,
+        compute: ([T]) -> Result
+    ) -> Result {
+        return self.collection.cached(key: key, compute: compute)
     }
     
 }
@@ -536,8 +473,6 @@ extension SyncedCollection: RandomAccessCollection {
         }
         set(newValue) {
             self.collection.update(newValue, index: index, actionOption: .standard)
-//            self.collection.items[index] = newValue
-//            self._triggerWrite = true
         }
     }
 }

LeStorage/WebSocketManager.swift

@@ -19,6 +19,7 @@ class WebSocketManager: ObservableObject {
     
     fileprivate var _reconnectAttempts = 0
     fileprivate var _failure = false
+    fileprivate var _error: Error? = nil
     fileprivate var _pingOk = false
     
     init(storeCenter: StoreCenter, urlString: String) {
@@ -59,10 +60,13 @@ class WebSocketManager: ObservableObject {
             switch result {
             case .failure(let error):
                 self._failure = true
+                self._error = error
                 print("Error in receiving message: \(error)")
                 self._handleWebSocketError(error)
             case .success(let message):
                 self._failure = false
+                self._error = nil
+                self._reconnectAttempts = 0
                 switch message {
                 case .string(let deviceId):
 //                    print("device id = \(StoreCenter.main.deviceId()), origin id: \(deviceId)")
@@ -90,7 +94,7 @@ class WebSocketManager: ObservableObject {
     private func _handleWebSocketError(_ error: Error) {
 //        print("WebSocket error: \(error)")
         
-        // Exponential backoff for reconnection
+        // up to 10 seconds of reconnection
         let delay = min(Double(self._reconnectAttempts), 10.0)
         self._reconnectAttempts += 1
         
@@ -131,7 +135,17 @@ class WebSocketManager: ObservableObject {
     var pingStatus: Bool {
         return self._pingOk
     }
+    
     var failure: Bool {
         return self._failure
     }
+    
+    var error: Error? {
+        return self._error
+    }
+    
+    var reconnectAttempts: Int {
+        return self._reconnectAttempts
+    }
+    
 }